Considering the reabsorption and thermal lens of Nd:YAG crystal when the laser operates on the transitions at 946 nm, a ring laser cavity formed by four mirrors was designed. Using a Brewster plate as a polarizer, a half-wave-plate and a TGG crystal as the optical diode and PPKTP as the frequency doubling crystal, a laser diode end-pumped 473 nm continuous wave single frequency Nd:YAG laser was demonstrated experimentally. The single frequency output power at 473 nm is 770 mW with pump power of 20 W. The long term power fluctuation is less than ±2.2%. After the laser was locked to the confocal Fabry-Perot cavity resonance, the measured frequency stability of blue laser is better than ±5 MHz/min.